Method for obtaining various gases and recovering by-products



Aug. 11, 1931. L. CHAVANNE 1,818,533

METHOD FOR OBTAINING VARIOUS GASES AND RECOVERING BY-PRODUCTS Tiled Jan; 50, 192:5

Patented Aug. 1931 LOUIS CHAVANNE,

PATENT OFFICE OF PARI S, FRANCE mnrrrop roa OBTAINING VARIOUS GASES Am) nncovnnme mnrnonuca's Application filed January 80, 1926, Serial No. 85,050, and in Belgium February 12, 1925.

This invention relates to a continuous process of low temperature distillation for solid fuels, the residue of which is preferably gasified by the method of fusion of the ashes employin the whole or part of the means describerfin my co-pending applications Serial No. 8,810, filed February 12, 1925, and Serial No. 32,790, filed May 25,

1o The process is applicable to the low temperature distillation of a moving mass of ituminous fuel, such as coal, lignite, oil Shale and the like, subjected to the action of a counter-current of hot rising gases, such 16 as those produced in a slagglng gas producer, within an extended zone of distillation, the temperature gradient of which is very small. This zone of distillation is provided with contiguous series'of internal so openings or orifices of suitable dimensions, so that the fuel contained within said zone virtually comprises a series of adjacent, narrow layers, each layer, which is a fraction of the fuel mass within the distillation zone,

corresponding to one series of orifices of the same isothermic region. These orifices are placed around the peripheries of the respective layers, and since no devices are inserted within the body of the fuel mass so itself for withdrawing vapor laden gases therefrom, the mass stands as a body void of empty spaces, except for those which are naturally due to the ordinary filling of a column with solid fuel of the type described.

Other series of external openings or orifices are provided with devices for the regulation and discharge of the fractional flows of ases and vapors evolved in each layer.

e space between said internal and external orifices comprises a series of collecting chambers which, being filled with vapor laden gases, thus provide'a mass of gases surrounding the moving fuel body which acts as an effective insulating agent.

Owing to the reduced temperature gradient, the difference of temperatures between an; two adjoining layers amountsto only a ew degrees. Being gradually heated by the hot gases rising successively throug each layer, the fuel, provided that it is conveniently sized and'that the fuel layers are not too extended, releases at each layer a single primary hydrocarbon portion with a definite boiling point; that is to say, a fractional. distillate.

If the zone of distillation and the orifices of evacuation are given suitable shapes, dimensions and arrangements, condensation of the hydrocarbon vapors in the mass of fuel will be practically avoided, and the said vapors will be carried awa by gas flows and collected fractionally in the primary form, and separately, in condensers of any suitable type connected to each external evacuating orifice, or to each series of said orifices, according to the arrahgement used. Alteration of the quality and reduction in the yield of the products, more particularly of those of low boilin point, are thus prevented.

Owing to t e shape of the fuel body subjected to distillation, and to the positions of the orifices around theperipheries of the layers, the gases and vapors of hydrocarbon portions are diverted rom every portion of each layer and the isothermic surfaces of said layers are practically parallel, although not necessarily horizontal. Owing to the balanced regimen of temperatures existing within the successive layers, there is no superheated portion of said layers where the fractional primary hydrocarbon portions might be destroyed.

Wide and numerous orifices will ensure the evacuation of the gases and vapors at a relatively low speed, so that the carrying away of dust is greatly reduced. By suitably .regulating t e gaseous flows escaping from the various ori zone, the temperature of each fuel layer. of the distillation zone may be varied; this renders it possible to also vary the grades of the condensible hydrocarbon portions carried away by the gases and to separate one from the other according to their specific gravities, that is, fractionating by layers the fuel mass distillates, or to collect several of these fractional distillates to gether. With such a regulation, it is possible even to obtain separately all successive grades of primary liquid hydrocarbon cos of ,the distillation The regulation of the temperatures in the zone of distillation, and consequently the variation in quality and quantity of fractionate condensible by-products, may be obtained by utilizing the means enumerated in the above mentioned applications Serial No. 8,810 and Serial No. 32,790. As disclosed therein, an extended zone 'wherein distillation is effected at relatively low temperatures is maintained above a very hot, and preferably thin, zone of fusion in a slaggmg gas producer by creating in the fuel column, at selected levels, certain exothermic and endothermic effects whereby a suitable regimen or gradient of temperatures is maintained extending from the hot zone of fusion to the top of the extended zone of distillation. The gas temperature within the lower portion of the fuel columns may be around 1500 C. and above, and decreases progressively as the gases rise through the solids so as to be reduced to 350 C., and even less, at the upper level of the charge.

The exothermal effects are produced by blowing at the bottom of the fuel column a blast of air or other fluid mixtures. which contain free oxygen, or of other fluids producing with the fuel endothermic reactions, said blast being heated to a temperature which is mainly dependent upon its free oxygen content and on the nature of the combustible mixture to be treated. The developed heat should be high enough to melt completely the ashes-and any additions in the fuel charge so that the molten residue is homogeneous and fluid.

For stable operation and maintenance of an extendedzone of low temperature distillation having a slow gradient it is sometimes necessary to localize at different levels in the fuel column certain endothermic effeets of desired intensit These endothermic eifects may be pro uced by any of the following steps:

a. The withdrawal or diversion of a portion of the hot gases of gasification at suitable levels of the fuel column, as between tliezone of fusion and the zone of distillation;

b. The injection into the hot zone of the producer of fuel dust or fluids having endothermic reactions, such as steam, carbon dioxide, etc.

c. The addition to the fuel of selected materials such as lean ore, limestone, iron and steel scraps, etc., the heating, fusion, volatilization, and decomposition of which at certain temperatures (and consequently within certain layers of the fuel body) absorb heat.

All of these means may be used simul taneously, or any of them independently of the others, for the regulation-and maintenance of a thin zone of fusion at high temperature and an extended zone of distillation at progressively decreasing low temperatures, from'which gases are withdrawn carrying out a maximum quantity of high grade 'condensible hydrocarbon portions. Moreover, regulating the diversion of gases out of the zone of distillation also causes changes in the temperatures of solid materials reaching the zone of fusion, and thereby modifies the workingconditions of said zone.

In order to make the invention clearly understood I will give, by way of example vwhich in no way affects its scope, the following description of one application whichwill show how the fractionated zone of dis tillation is constituted, and how the gases and'vapors of hydrocarbon portions carried away are extracted.

The fuel continuously charged at the top of a distillation retort of any suitable shape and section preferably forms a vertical column at the base of which the solid residue is gasified by the method of fusion of the ashes. The distillation zone of said column is provided with a series of annular boxes or chambers of generally frusto-conical shape arranged one above the other, one of their sides forming the walls of the shaft; their arrangement shows preferably no constriction ofthe profile line, each chamber bein open in one or more ways to the gases an vapors evolved in the fuel body, and each being provided with one or more outlet pipes connected to a condensing plant (not shown).

Figures 1 to 4 inclusive, are diagrammatic vertical sectional views of a gas producer illustrating the flow of gases that may be secured through the same; and

Figure 5 is an enlarged side elevation and section of a portion of a producer illustrating the means for carrying out the present invention.

In the drawings there is shown, as one embodiment of the present invention, a slagging gas producer whose c lindrical or slightly conical shaft is provi ed at the top with a fuel charging apparatus F of a known, and preferably of a continuous distribution, type. The bottom portion or crucible of the producer is provided with at least one tap hole S for running off the slag and hole R for tapping molten metal. Above the crucible is a primary row of blast twyers B throu h which is blown a blast of air or other uid mixture containing'free oxygen. A second row of twyers E, situated above the blast twyers, serves to a I inject into the hot zone of the producer fuel dust, or fluids with'endothermic reactions such as steam or carbon dioxide. The producer shaft is also provided adjacent its top with gas outlets such as O, and with a suitable number of outlets arranged at a. point situated above the level where the ashes are melted and below the bottom level of the distillation zone; T and T are gas mains fitted with controlling apparatus such as valves V and V and suitable suction fans (not shown). By varying the suction of said fans and the positions of valves V and V a continuous flow of the gases within the producer can be maintained andregulated in any desired manner as indicated by arrows f f and f in Figs. 1-4.

The gradual heating of the fuel mass filling the zone of distillation is effected progressively and as desired by allowing the passage therethrough of a suflicient proportion ofsthe hot ascending combustible gases to give the desired temperatures atvarious portions of the column, which temperatures,

it willbe understood, can be continuously ascertained by the usual pyrometers. This passage or flow of hot ascending combustible gases is in turn effected by controlling valves V and V as well as by regulating the blast supplied through twyers B.

The extension of the zone of distillation is obtained by increasing the number of the outlet orifices O and their distance apart. It

is then possible to maintain suitable gradu-.

ated temperatures in the successive layers of the distillation zone, and to collect separavrately at each conveniently selected level the gases carrying the grade ofprimary con densible hydrocarbon portions evolved at said level. The hydrocarbon portions thus obtained from the various layers will vary from those-having a maximum amount of low boiling oils to those having increasing percentages of high boiling oils containing tars and waxy products, according to the position of the layer the distillation zone and its corresponding level in the scale or temperatures, the grade of the products also depending upon the nature of the fuel submitted to distillation. It is also possible to collect separately a greater or lesser percentage of certain grades of primary condensible hydrocarbon portions by adjusting correspondingly the diverted portions of gases escaping at levels where the prevailing temperatures allow the removal of said grades of products. In the above cases, primary condensible hydrocarbon portions are obtained, which means that they remain unaltered in the producer and as evolved. They can be collected, however, not only separately at the various levels, but also as mixtures of those evolved at a plurality of levels with evidently some variation in quantities,

1 their production corresponding to the efiects of the direct flow of ascending gases.

Again, if for a g the usual series 0 various hydorcarbon portions, the production of certain ades is desired regardless of the productlon of other grades, then the invention permits the easy obtainment of any particular grade of these hydrocarbon portions by maintaining a suitable balance of temperature and pressures at the level or levels where the required grade is evolved. Thus a high boiling oil can be obtained in maximum amounts by closing the valves at the to v of the column and thereby causing the ighter products to pass through the lower hot zone, in

iven fuel, WhlOh can yield I which case, the production of'primary conbe recovered separately (or may be mixed' together and then recovered) in a condensing plant (not shown), if desired.

In order to carry out this fractional distillation process, the. device illustrated in Figure 5 may be employed, the shape and details of w ich may vary within wide limits. This device constitutes the upper portion of a gas producer surrounding the zone of distillation, or the portionto be added to any existing gas producer which will, also. be preferably fitted with gas ofttakes located above the scorification zone and with an extended distillation zone. It comprises rings A, A A etc., mounted u on circular members M, said rings being pre rably frusto-conical and forming with such members a series of annular collecting chambers. 0, C G etc., closed at their upper parts, each one being independent of the other and being connected with a by-procluct condensing plant (not shown through separate pipes t, t t etc., provi ed with valves '0, 'v 11 etc.

sizes and numbers, and also can be insulated or not.

At will be seen from the arrows, the gases carrying with them the condensible by-prodnets of distillation, pass separately through the wide, internal, annular openings or orifices in the boxes C, C G2, etc., and from there to the condensing plant (not shown), through the separate, external orifices or pipes t, t t etc., where the various grades of gy-products so separated are then recovere Should it be desired,-instead of collectin separately each primary grade. of condensible hydrocarbon portions, to collect a mixture or mixtures of various grades, it will be understood that this can be accomplished by any known means for combining the output of the various pipes t, t t2,.etc.

The large exits provided for the currents of gases laden with by-product vapors, and the off-takes provided with suitablecontrol means, allow the perfect maintenance of a gradient of temperature within the whole distillation zone as well as the maintenance of balanced temperature and pressure at each level of said zone, the even flow of gases and their quick exhaust without alteration of the primary grades of condensible hydrocarbon portions whenever formed.

It will be also noted that by locating the orifices for the extraction of the gases and vapors around the periphery of the fuel body, it is not necessary to insert any device within the fuel mass itself to withdraw therefrom the vapor laden gases, and the mass therefore stands as a body void of empty spaces, except for those which are naturally due to the filling of a column with ordinary solid fuel. Also, since boxes C, C G etc., are filled with "vapor laden gases, the fuel body is thus surrounded by a mass of gases which act as an effective insulating agent, thereby assisting in the prevention of condensation of the hydrocarbon'portion vapors within the fuel body.

It will be obvious that the invention is not limited to the form shown in the drawings, but is capable ofa variety of mechanical embodiments. counter-current of combustible gas need not be generated within the same structure as that in which distillation takes place, but may be supplied thereto in any suitable manner. Various other changes, which will now appear to those skilled in the art, may be made in the form, details of construction and arrangement of the parts without departing from the spirit of the invention, and reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is q 1. A continuous low temperature distillation process, applied to a body of fuel mov- For example, the hot ing throu h and in contact with a countercurrent of combustible heating as, which ggiiprises maintaining within said moving 3 distillation zone of slow gradient, diverting gas flows from the peripheries of a; series of adjacent narrow layers of said distillation zone, each of said flows carrying out of the'corresponding layer vapors of one grade of primary hydrocarbon portions, each layer yielding a different grade, and collecting each rade of said vapors separately.

2. continuous low temperature distillation process, applied to a body of fuel moving throu h and in contact with a countercurrent of combustible heating gas, which comprises maintaining within said moving body of fuel an extended low temperature distillation zone of slow gradient, diverting gas flows through large openings in the peripheries of a series of adjacent narrow layers of said distillation zone, each of said flows carrying out of a corresponding layer vapors of one grade of primary hydrocarbon portions, each layer yielding a different grade ranging from the lightest at the upper part of the distillation zone to the heaviest at the lower part, and collecting each grade of said vapors separately.

3. A continuous low temperature distillation recess, applied to a body of fuel moving t rough and in contact with a countercurrent of combustible heating gas, which comprises maintaining within said moving body of fuel an extended low temperature distillation zone of slow gradient, diverting gas flows from the peripheries of a series of adjacent narrow layers of said distillation zone, certain of said flows each carrying out of the corresponding layer vapors of one grade of primary hydrocarbon portions, other flows carrying out a' mixture of grades, and collecting each grade and mixture of grades separately.

4. A continuous low temperature distillation process, applied to a body of fuel moving through and in contact with a countercurrent of combustible heating as, which comprises maintaining within said moving body of fuel an extended low temperature distillation zone of slow gradient, diverting gas flows from the peripheries of a series of adjacent narrow layers of said distillation zone, the flows diverted from the hotter layers each carrying out therefrom a mixture of grades of heavier hydrocarbon portions, the flows diverted from the cooler layers each carrying vapors of one grade of lighter primary hydrocarbon portions, and collecting each grade and mixture of grades separately.

5. A continuous low temperature distillation process, applied toa body of fuel moving through and in contact with a countercurrent of combustible heating gas, which of fuel an extended low temperature comprises maintaining within said moving body of fuel an extended low temperature distillation zone of slow gradient, diverting gas flows from the peripheries of a series of adjacent narrow layers of said distillation zone, the flows diverted from the cooler layers each carryin out therefrom a mixture of grades of lig ter hydrocarbon portions, the flows diverted from the hotter layers each carrying vapors of one grade of heavier primary hydrocarbon portions, and collectmg each grade and mixture of grades separately.

6. A continuous low temperature distillation process, applied to a body of fuel moving through and in contact with a countercurrent of combustible heating gas, which comprises maintaining within said moving body of fuel an extended low temperature distillation zone of slow gradient,'diverting gas flows from theoperipheries of a series of adjacent narrow layers of said distillation zone, each of said flows carrying out of the corresponding layer vapors of one grade of oil, each layer yielding a different grade ranging from low-boilmg to high-boiling tion rocess, ap lied to a body of fuel moving t rough an in contact with a countercurrent of combustible heating gas, which comprises maintaining within said moving regions of the fuel body, diverting gas flows v from'the peripheries of a series of adjacent narrow layers of said distillation zone, each of said flows carrying out of the corresponding layer vapors ofone grade of primary hydrocarbon portions, each layer yielding a different grade from the lightest to the heaviest, said flows also carrymg vapors of said heat absorbing materials, and collectin the vapors from each layer separately.

11 testimony whereof I have affixed my signature.

LOUIS GHAVANNE.

oils, and collecting each grade of said vapors segarately;

A continuous low temperature distillation process, applied to a body of fuel moving t rou h and in contact with a countercurrent 0 combustible heating gas, which comprises maintaining within said moving body of fuel an extended low temperature distillation zone of'slow gradient, introducing in the hot portion of said fuel body fluids such as steam and "carbon dioxide which react endothermically with the fuel, diverting gas flows from the eripheries of a series 0 adjacent narrow ayers of said distillation zone, each of said flows carrying out of the corresponding layer vapors of one grade of primary hydrocarbon portions, each layer yielding a different grade,

and'collecting the vapors from each layer separately.

8. A continuous low temperature distillation rocess, applied to a body of fuel moving t rou h and in contact with a countercurrent 0 combustible heating comprises maintaining within said moving body of fuel an extended low temperature distlllation zone of slow gradient, mixing gas, which with the fuel materials to absorb heat in various re 'ons of the fuel body, divertin gas flows rom the peripheries of a series 0 adjacent narrow la ers, of said distillation zone, each of said ows carrying out of the 'correspondin hyd r layer vapors of one grade of primary ocarbon portions, each layer yielding a different grade from the lightest to the heaviest, said flows also carrying vapors of said heat absorbing materials, and collecting the vapors from each layer separately.

9. A continuous low temperature distilla- 

